1. Field of the Invention
The present invention relates to a drive motor control method and a printer and, more specifically, to a technology field of making a predetermined operation section operate appropriately by exercising control over the drive state of a drive motor based on an initial operation time measured for the operation section.
2. Description of the Related Art
Some printers perform image printing by thermal transfer printing, laser printing, or others for printing on sheets including photographic paper and photographic film. With such printers, their cabinets each carry therein predetermined operations sections, e.g., a sheet extraction mechanism that extracts printing sheets from a sheet tray, a sheet transfer mechanism that transfers the printing sheets, a roller movement mechanism that moves rollers of the sheet transfer mechanism to their appropriate positions, a head drive mechanism that moves a photographic head to its appropriate position for image printing on the printing sheets, and a sheet cutting mechanism that cuts the printed sheets into any predetermined size.
The components of these operation sections often operate in response to the driving force of a drive motor, e.g., direct-current motor, and the drive motor is under the control of a control section equipped with a microcomputer or others.
A printer using a continuous roll of printing sheet is provided with a sheet cutting mechanism, for example. The cutter of the sheet cutting mechanism rotates and moves in the direction across the printing sheet by a drive motor so that the printing sheet is accordingly cut.
The sheet cutting mechanism is provided with a fixed blade extending in the cutting direction of the printing sheet, a stopper disposed at the limit edge of a cutter to move, and a sensor that detects the position of the cutter after movement. The drive motor rotates the cutter while making it slide in contact with the fixed blade so that the printing sheet is cut. After the cutting of the printing sheet, the sensor detects the limit edge of the cutter to move, and the drive motor stops driving. At the same time, a carriage supporting the cutter to freely rotate comes into contact with the stopper so that the carriage and the cutter both stop moving.
The problems with such a previous printer are that the large shock and a lot of noise due to collision of the carriage with the stopper are generated, and that the carriage does not stop at its predetermined position due to the rebound by the collision with the stopper. These are caused because the drive motor is defined by driving conditions based on maximum load, i.e., based on startup of the drive motor for the sheet cutting mechanism, and the drive motor is typically under the high drive voltage, i.e., not only at the startup thereof but also until the cutter completes the cutting of the printing sheet. This thus results in the faster movement speed of the cutter, thereby increasing the inertial force, which is the cause of the above problems.
In order to solve such problems, considered is a possibility of applying a low drive voltage to the drive motor from the startup thereof, but this may cause another problem of failing to appropriately start the drive motor, or taking longer time to cut the printing sheet due to the low-speed rotation of the drive motor, for example.
To solve such problems, some previous printers control the rotation speed of a drive motor to operate appropriately, e.g., prevent the shock and noise as above from being generated. For the purpose, the parameter data about the control of the drive motor is measured in the test before shipment, and the measurement result is stored in a nonvolatile memory to be read and corrected as appropriate when the drive motor is driven. As an example, refer to Patent Document 1 (JP-A-2004-284367)